Cooling assembly for hammer bank

Abstract

A cooling apparatus for a hammer bank assembly of an impact printer. The cooling apparatus directs air onto each hammer and magnet of the hammer bank assembly and maintains the temperature differential of the hammers and magnets within predetermined ranges.

I claim: 
     
       1. An apparatus for minimizing temperature changes of a plurality of interleaved print hammers and magnets in an impact printer hammer bank assembly, wherein the magnets are supported by a frame member, and each pair of adjacent magnets defines a gap therebetween, and wherein each print hammer has an electromagnetic coil which is disposed within a gap, said apparatus comprising: a fan for producing a flow of air; and   duct means for directing the flow of air from the fan into each gap between adjacent magnets, the duct means including a plurality of conduits passing through the frame member and having outlets located in the frame member, each conduit having a nozzle for accelerating the flow of air, and said outlets being positioned adjacent the plurality of hammers and magnets and aligned with respect to the hammers and magnets so that accelerated air exiting from each outlet passes directly into a gap and past the hammer coil and magnets of the gap to dissipate excess heat generated by the coils to thereby minimize temperature increases in the hammers and magnets caused by the operation of the hammer bank assembly.   
     
     
       2. The apparatus of claim 1 wherein the duct means further comprises a manifold mounted on rear of the frame member over the conduits, for receiving air from the fan and directing air to the conduits. 
     
     
       3. The apparatus of claim 1 wherein each outlet is aligned with a hammer such that the flow of air exiting a frame member outlet is directed toward a particular hammer and the magnets adjacent that hammer. 
     
     
       4. The apparatus of claim 1 further comprising first and second sealing strips, located adjacent the frame member at the top and bottom of the magnets, respectively, for minimizing the escape of air between the frame member and the magnets before the air passes through the gaps between the magnets. 
     
     
       5. The apparatus of claim 4 wherein the sealing strips abut the hammers when the hammers are in a rest position. 
     
     
       6. An impact printer hammer bank assembly, comprising: a plurality of print hammers each having a planar body having a coil therein;   a plurality of magnets;   a frame member for supporting the hammers and magnets aligned in at least one row on the frame member with each adjacent pair of magnets defining a gap, wherein said hammers and magnets are interleaved and a hammer is disposed within each gap, said frame member having a plurality of air conduits, each conduit having a plurality of outlets associated with each hammer within a gap, said outlets being adjacent the hammers and magnets and linearly aligned in registration with the associated hammer;   a fan for producing a flow of air; and   a manifold carried on the frame member coupled to the conduits and having an inlet operably connected to the fan, said manifold for directing air from the fan to the frame member outlets such that air exiting from each plurality of outlets associated with a particular hammer exits directly into the gap and around either side of the hammer body to dissipate excess heat generated by the hammer coils to thereby minimize temperature increases in the hammer and magnets caused by the operation of the hammer bank assembly.   
     
     
       7. The apparatus of claim 6 wherein each outlet has a nozzle for accelerating the flow of air exiting the outlet. 
     
     
       8. The apparatus of claim 7 wherein the magnets on either side of a particular hammer partially block the outlets associated with that hammer such that the flow of air is further accelerated. 
     
     
       9. The apparatus of claim 8 further comprising lubricating tabs located between adjacent hammers and magnets to reduce friction therebetween and to insure a space between adjacent hammers and magnets to facilitate the flow of air between the hammers and magnets. 
     
     
       10. An apparatus for limiting the temperature differential of a plurality of hammers and magnets in an impact printer hammer bank assembly wherein each hammer has a coil disposed therein, said apparatus comprising: a frame member for supporting the hammers and magnets aligned in an upper row and in a lower row on the frame member, each adjacent pair of magnets defining a gap and the hammers and magnets being interleaved with a hammer disposed within each gap, said frame member having a plurality of air conduits having outlets arranged in an upper rectangular matrix facing the upper row of hammers and magnets and a lower rectangular matrix facing the lower row of hammers and magnets, with a vertical column of outlets of each matrix being being adjacent to and aligned with a gap between adjacent magnets;   a fan for producing a flow of air;   an upper manifold carried on the frame member for directing air to the upper matrix of outlets and having an inlet operably connected to the fan and a lower manifold carried on the frame member for directing air to the lower matrix of outlets and having an inlet operably connected to the upper manifold, said manifolds for directing air from the fan through the conduits to the conduit outlets so that air exiting from each vertical column of outlets passes directly over the hammer within the associated gap and directly over the magnets flanking the gap to dissipate excess heat generated by the hammer coils and to maintain the temperature differential of the hammer within the gap and the magnets defining the gap within a predetermined range.   
     
     
       11. A hammer bank assembly for use in an impact printer, comprising: a frame;   a plurality of magnets secured to the frame in a spaced linear array, wherein each pair of adjacent magnets has a gap therebetween;   a plurality of print hammers, each having a generally planar body having a coil therein, wherein the print hammers the magnets so that a hammer body is located within each gap; and   cooling means for directing a stream of fluid directly into each of the gaps onto a hammer body in each gap, said cooling means including a plurality of conduits passing through the frame and terminating in an outlet adjacent to and aligned with the hammers and the gaps between the magnets, wherein there is at least one outlet corresponding to each hammer and gap, said cooling means further including a blower for providing air flow and a manifold for coupling air from the blower to the conduits to thereby minimize temperature increases in the hammers and magnets caused by operation of the hammer bank assembly.   
     
     
       12. The hammer bank assembly of claim 11 wherein the magnets are ceramic magnets.